NSNotification.Name.UIKeyboardWillShow崩溃-无法找到原因 [英] NSNotification.Name.UIKeyboardWillShow crash - Unable to find cause

问题描述

我的应用程序的用户报告了一次随机崩溃。我已经集成了CrashAnalytics，其中提供了以下详细信息：

  __ CFNOTIFICATIONCENTER_IS_CALLING_OUT_TO_AN_OBSERVER__ + 20 
  

所示的行号为154，即：

  self.notesView.content.frame = CGRect（x：self.notesView.content.frame.origin .x，y：self.notesView.content.frame.origin.y，宽度：self.notesView.content.frame.size.width，高度：self.notesView.content.frame.size.height-keyboardFrame.size.height ）。 
  

以下是我编写的包含以下内容的代码：

 重写功能viewWillAppear（_动画：Bool）{
 super.viewWillAppear（动画）
 label_title.addObserver（self，forKeyPath： contentSize ，选项：.new，上下文：无）
 NotificationCenter.default.addObserver（自身，选择器：#selector（keyboardShown），名称：NSNotification.Name.UIKeyboardWillShow，对象：无）； 
 NotificationCenter.default.addObserver（自身，选择器：#selector（keyboardHide），名称：NSNotification.Name.UIKeyboardWillHide，对象：无）; 
} 
 
覆盖func viewWillDisappear（_b动画：Bool）{
 super.viewWillDisappear（动画）
 label_title.removeObserver（self，forKeyPath： contentSize）
 NotificationCenter.default.removeObserver（自身，名称：NSNotification.Name.UIKeyboardWillShow，对象：无）
 NotificationCenter.default.removeObserver（自身，名称：NSNotification.Name.UIKeyboardWillHide，对象：无）
} 
 
 func keyboardShown（notification：NSNotification）{
 let info = notification.userInfo！ 
让keyboardFrame：CGRect =（info [UIKeyboardFrameEndUserInfoKey] as！NSValue）.cgRectValue 
 self.notesView.content.frame = CGRect（x：self.notesView.content.frame.origin.x，y： self.notesView.content.frame.origin.y，宽度：self.notesView.content.frame.size.width，高度：self.notesView.content.frame.size.height-keyboardFrame.size.height）
 } 
  

首先，这是相当随机的，但我从不了解。其次，我无法找到确切的原因。这是因为通知观察者还是因为notesView（不是nil）。

如建议的

Users of my app have reported a random crash. I have integrated CrashAnalytics which is giving the following details :

__CFNOTIFICATIONCENTER_IS_CALLING_OUT_TO_AN_OBSERVER__ + 20. 

The line number indicated is 154, which is :

self.notesView.content.frame = CGRect(x: self.notesView.content.frame.origin.x, y: self.notesView.content.frame.origin.y, width: self.notesView.content.frame.size.width, height: self.notesView.content.frame.size.height - keyboardFrame.size.height). 

Following is the code I have written which consist of this line :

override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        label_title.addObserver(self, forKeyPath: "contentSize", options: .new, context: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(keyboardShown), name:NSNotification.Name.UIKeyboardWillShow, object: nil);
        NotificationCenter.default.addObserver(self, selector: #selector(keyboardHide), name:NSNotification.Name.UIKeyboardWillHide, object: nil);
    }

    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)
        label_title.removeObserver(self, forKeyPath: "contentSize")
        NotificationCenter.default.removeObserver(self, name: NSNotification.Name.UIKeyboardWillShow, object: nil)
        NotificationCenter.default.removeObserver(self, name: NSNotification.Name.UIKeyboardWillHide, object: nil)
    }

    func keyboardShown(notification: NSNotification) {
        let info = notification.userInfo!
        let keyboardFrame: CGRect = (info[UIKeyboardFrameEndUserInfoKey] as! NSValue).cgRectValue
        self.notesView.content.frame = CGRect(x: self.notesView.content.frame.origin.x, y: self.notesView.content.frame.origin.y, width: self.notesView.content.frame.size.width, height: self.notesView.content.frame.size.height - keyboardFrame.size.height)
    }

Firstly, this is quite random and I never get it. Secondly, I am not able to find exact cause for it. Is this because of notification observer or because of notesView (which is not nil).
As suggested here, should I remove keyboard notification observer in deinit ?
Please guide me through this if someone has experienced this previously.

解决方案

Change signature of your function to this

@objc func keyboardShown(_ notification: Notification)

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